function today() {
    var now = new Date();
    var year = now.getFullYear();
    var month = now.getMonth() + 1;
    var date = now.getDate();
    var hour = now.getHours();
    var minute = now.getMinutes();
    var second = now.getSeconds();
    var str = year;
    str +="-"+(month < 10? '0'+month : month);
    str +="-"+(date <10?'0'+date: date);
    str +=" "+(hour <10?'0'+hour: hour);
    str +=":"+(minute<10?'0'+minute:minute);
    str +=":"+(second<10?'0'+second:second)
    return str;
}